Lighting apparatus and automobile including the same

ABSTRACT

A lighting apparatus for vehicle use that projects light forward includes: a base, a low beam lamp including a low beam light emitting device disposed on the base; a first high beam lamp including a first high beam light emitting device disposed on the base; a second high beam lamp including a second high beam light emitting device disposed on the base; and a lighting controller configured to turn on the low beam light emitting device, the first high beam light emitting device, and the second high beam light emitting device when high beams are turned on. A center of an area illuminated by the first high beam lamp and a center of an area illuminated by the second high beam lamp are horizontally spaced apart from each other.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority of Japanese PatentApplication Number 2014-098145, filed May 9, 2014, the entire content ofwhich is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present disclosure relates to a lighting apparatus and an automobileincluding the lighting apparatus.

2. Description of the Related Art

Vehicles such as automobiles are equipped with headlights in the front.These headlights include a housing (chassis) and a lighting apparatusattached to the housing.

Lighting apparatuses used in vehicle headlights include, for example, abase, a low beam light emitting device and a high beam light emittingdevice disposed on the base, and a lens positioned in front of the lowbeam light emitting device and the high beam light emitting device (seeJapanese Unexamined Patent Application Publication No. 2005-108554).

Examples of conventional low beam light emitting devices and high beamlight emitting devices used include high intensity discharge (HID)lamps. In recent years, due to the luminous efficiency and long lifespanof light emitting diodes (LEDs), which exceed HID lamps, lightingapparatuses using LEDs as the low beam light emitting devices and highbeam light emitting devices have been researched and developed.

SUMMARY OF THE INVENTION

With the conventional lighting apparatus described above, powerconsumption cannot be reduced.

For example, when the high beam light emitting device is used, a widearea, spanning from directly in front of the driver to far away from thedriver, must be brightly illuminated. To brightly illuminate this widearea, the high beam light emitting device must output enough light toachieve an extremely high illuminance, which results in excessive powerconsumption.

An object of the present disclosure is to provide a lighting apparatusand automobile capable of reducing power consumption.

In order to achieve the aforementioned object, according to one aspectof the present disclosure, a lighting apparatus for vehicle use thatprojects light forward is provided. The lighting apparatus includes: abase; a low beam lamp including a low beam light emitting devicedisposed on the base; a first high beam lamp including a first high beamlight emitting device disposed on the base; a second high beam lampincluding a second high beam light emitting device disposed on the base;and a lighting controller configured to turn on the low beam lightemitting device, the first high beam light emitting device, and thesecond high beam light emitting device when high beams are turned on. Acenter of an area illuminated by the first high beam lamp and a centerof an area illuminated by the second high beam lamp are horizontallyspaced apart from each other.

Accordingly, power consumption can be reduced.

BRIEF DESCRIPTION OF DRAWINGS

The figures depict one or more implementations in accordance with thepresent teaching, by way of examples only, not by way of limitations. Inthe figures, like reference numerals refer to the same or similarelements.

FIG. 1 is a front view of an automobile according to an embodiment ofthe present disclosure;

FIG. 2 is a perspective view of a lighting apparatus according to anembodiment of the present disclosure;

FIG. 3 is a front view of a lighting apparatus according to anembodiment of the present disclosure;

FIG. 4 is a top view of a lighting apparatus according to an embodimentof the present disclosure;

FIG. 5 is a cross sectional view of a lighting apparatus according to anembodiment of the present disclosure taken at line A-A in FIG. 4;

FIG. 6 is a cross sectional view of a lighting apparatus according to anembodiment of the present disclosure taken at line A-A in FIG. 4,illustrating paths of light emitted when the high beams and low beamsare in use;

FIG. 7 illustrates a driving lane for an automobile according to anembodiment of the present disclosure and an oncoming traffic lane;

FIG. 8 illustrates an area illuminated by a lighting apparatus accordingto an embodiment of the present disclosure when the low beams are inuse;

FIG. 9 illustrates an area illuminated by a lighting apparatus accordingto an embodiment of the present disclosure when the high beams are inuse;

FIG. 10 illustrates an area illuminated by a first high beam lampincluded in a lighting apparatus according to an embodiment of thepresent disclosure;

FIG. 11 illustrates an area illuminated by a second high beam lampincluded in a lighting apparatus according to an embodiment of thepresent disclosure; and

FIG. 12 is a block diagram illustrating a configuration relating tolighting functions of an automobile according to an embodiment of thepresent disclosure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Hereinafter, a lighting apparatus and automobile according to anembodiment are described in detail with reference to the accompanyingdrawings. Note that the embodiment described below shows a specificpreferred example of the present disclosure. Therefore, the numericalvalues, shapes, materials, structural elements, arrangement andconnection of the structural elements, etc., shown in the followingembodiment are mere examples, and are not intended to limit the presentdisclosure. Consequently, among the structural elements in the followingembodiment, elements not recited in any one of the independent claimswhich indicate the broadest concepts of the present disclosure aredescribed as arbitrary structural elements.

As described herein, “front” and “forward” refer to the direction inwhich light is emitted from the lighting apparatus (i.e., thelight-emitting direction) and the light-extraction direction in whichlight is extracted, and “back” and “behind” refer to the directionopposite the front/forward direction. Furthermore, “front” and “forward”refer to the direction of travel when an automobile moves forward,“right” and “left” are from the perspective of the driver, “up”,“upward”, and “above” refer to the direction toward the ceiling of theautomobile, and “down”, “downward”, and “below” refer to the directionopposite the up/upward/above direction. Additionally, the Z axiscorresponds to the anteroposterior directions, the Y axis corresponds tothe up and down (vertical) directions, and the X axis corresponds to theleft and right (horizontal, lateral) directions.

Note that the respective figures are schematic diagrams and are notnecessarily precise illustrations. Additionally, like structuralelements share the same reference numbers.

EMBODIMENT

First, automobile 100 according to an embodiment will be described withreference to FIG. 1. FIG. 1 is a front view of the automobile accordingto the embodiment.

As illustrated in FIG. 1, automobile 100 is one example of a vehicle,such as a four-wheeled automobile, and includes vehicle body 110 and apair of headlights 120 disposed on the left and right sides of the frontof vehicle body 110. Automobile 100 is, for example, an automobilepropelled by a gasoline engine or an automobile propelled by an electricengine.

In the embodiment, headlights 120 are headlight assemblies used in avehicle and include housing 121, front cover 122, and a lightingapparatus (not shown in FIG. 1) that is attached to housing 121 behindfront cover 122.

Housing 121 is, for example, a metal chassis and has an opening fromwhich light emitted from the lighting apparatus exits. Front cover 122is a headlight cover that transmits light and covers the opening ofhousing 121. Housing 121 and front cover 122 are sealed together so asto keep water and dust from entering housing 121.

The lighting apparatus is disposed behind front cover 122 and attachedto housing 121. The light emitted by the lighting apparatus transmitsthrough front cover 122 and travels outward.

Lighting Apparatus

Next, lighting apparatus 1 according to the embodiment will be describedwith reference to FIG. 2 through FIG. 6. FIG. 2 is a perspective view ofthe lighting apparatus according to the embodiment. FIG. 3 is a frontview of the lighting apparatus. FIG. 4 is a plan view of the lightingapparatus. FIG. 5 is a cross sectional view of the lighting apparatustaken at line A-A in FIG. 4. FIG. 6 is a cross sectional view of thelighting apparatus taken at line A-A in FIG. 4, and illustrates lightpaths of the light emitted when the high beam and the low beam are used.

Lighting apparatus 1 according to the embodiment is a vehicle lightingapparatus used in, for example, a vehicle headlight, and projects lightforward. As illustrated in FIG. 2 through FIG. 5, the main body oflighting apparatus 1 includes base 2, high beam lamp 3, and low beamlamp 4. More specifically, lighting apparatus 1 includes high beam lightsource module 10, low beam light source module 13, lens body 20, heatsink 30, and shield 40. Lighting apparatus 1 further includes a lightingcontroller (not shown in FIG. 2 through FIG. 5) that controls high beamlight source module 10 and low beam light source module 13.

As illustrated in FIG. 5, high beam light source module 10 includes highbeam light emitting device (first light emitting device) 11 andsubstrate 12 for high beam use. Low beam light source module 13 includeslow beam light emitting device (second light emitting device) 14 andsubstrate 15 for low beam use.

As illustrated in FIG. 5, lens body 20 is disposed in front of high beamlight source module 10 (high beam light emitting device 11) and low beamlight source module 13 (low beam light emitting device 14). Asillustrated in FIG. 4, lens body 20 includes high beam lens unit 21 andlow beam lens unit 22. High beam lens unit 21 is configured of threecollimating lenses—first collimating lens 21 a, first collimating lens21 b, and second collimating lens 21 c.

As illustrated in FIG. 5, heat sink 30 is configured of two heatdissipating components—first heat sink 31 thermally coupled to high beamlight emitting device 11 and second heat sink 32 thermally coupled tolow beam light emitting device 14.

In the embodiment, heat sink 30 and shield 40 together form base 2, andhigh beam light source module 10 and low beam light source module 13 aredisposed on base 2. In other words, high beam light emitting device 11and low beam light emitting device 14 are disposed on base 2.

As illustrated in FIG. 3, high beam light source module 10 and high beamlens unit 21 together form high beam lamp 3. High beam lamp 3 is anoptical system for producing a high beam having a desired lightdistribution pattern. More specifically, high beam lamp 3 includes firsthigh beam lamp 3 a, first high beam lamp 3 b, and second high beam lamp3 c.

As illustrated in FIG. 3, low beam light source module 13 and low beamlens unit 22 together form low beam lamp 4. Low beam lamp 4 is anoptical system for producing a low beam having a desired lightdistribution pattern.

Note that high beam lamp 3 and low beam lamp 4 may include other opticalcomponents. High beam lamp 3 and low beam lamp 4 will be described infurther detail later.

As illustrated in FIG. 3 and FIG. 4, high beam light source module 10,low beam light source module 13, lens body 20, heat sink 30, and shield40 are arranged so as to fit in a given circular region when viewedalong the Z axis, and in the embodiment, are arranged so as to fit in aφ70 mm region.

Hereinafter, each structural element will be described in detail.

Light Source Modules

High beam light source module 10 is an LED module for producing the highbeam, and is used to illuminate an area a far distance ahead. Low beamlight source module 13 is an LED module for producing the low beam, andis used to illuminate the road immediately ahead.

A plurality of high beam light emitting devices 11 (first high beamlight emitting device 11 a, first high beam light emitting device 11 b,and second high beam light emitting device 11 c) are mounted onsubstrate 12 in high beam light source module 10. In the embodiment,first high beam light emitting device 11 a, first high beam lightemitting device 11 b, and second high beam light emitting device 11 care mounted so as to correspond to first collimating lens 21 a, firstcollimating lens 21 b, and second collimating lens 21 c, respectively.More specifically, high beam light emitting device 11 emits light thattransmits through high beam lens unit 21. For example, high beam lightemitting device 11 emits light when lighting apparatus 1 projects thehigh beam.

Low beam light emitting device 14 is mounted on substrate 15 in low beamlight source module 13. More specifically, low beam light emittingdevice 14 emits light that transmits through low beam lens unit 22. Forexample, low beam light emitting device 14 emits light not only whenlighting apparatus 1 projects the low beam, but when the high beam isprojected as well.

High beam light source module 10 and low beam light source module 13are, for example, white light sources, such as B-Y white LED lightsources that use a blue LED chip and a yellow phosphor to emit whitelight. Alternatively, high beam light source module 10 and low beamlight source module 13 may be white LED light sources that use an LEDchip that emits red light, an LED chip that emits green light, and anLED chip that emits blue light to collectively emit white light.

Moreover, high beam light source module 10 and low beam light sourcemodule 13 may be surface mount device (SMD) modules, and alternativelymay be chip on board (COB) modules.

When high beam light source module 10 and low beam light source module13 are SMD modules, high beam light emitting device 11 and low beamlight emitting device 14 are each an SMD LED device that has an LED chip(bare chip) mounted and sealed with a sealant (phosphor-containingresin) in a resin package. When high beam light source module 10 and lowbeam light source module 13 are COB modules, high beam light emittingdevice 11 and low beam light emitting device 14 are each LED chipsthemselves, and are directly mounted on substrate 12 and substrate 15,respectively. In this case, the LED chips mounted on substrate 12 andsubstrate 15 are sealed with a sealant such as a phosphor-containingresin.

Substrate 12 and substrate 15 are, for example, ceramic substrates madeof, for example, alumina, resin substrates made of resin, or insulatedmetal substrates consisting of a metal baseplate covered by a layer ofinsulating material. Substrate 12 and substrate 15 have a shape in planview corresponding to the shape of the mounting surface on heat sink 30to which substrate 12 and substrate 15 are mounted.

High beam light source module 10 having such as structure is fixed tofirst heat sink 31 of heat sink 30. More specifically, substrate 12 ismounted and fixed to a predetermined mounting surface on first heat sink31. Moreover, in the embodiment, substrate 12 is arranged standing(i.e., vertically) so that high beam light source module 10 projectslight in a forward direction. In other words, the optical axis of highbeam light source module 10 (high beam light emitting device 11) isparallel to the Z axis.

Low beam light source module 13 is fixed to second heat sink 32 of heatsink 30. More specifically, substrate 15 is mounted and fixed to apredetermined mounting surface on second heat sink 32. Moreover, in theembodiment, substrate 15 is arranged laying flat (i.e., horizontally) sothat low beam light source module 13 projects light in an upwarddirection. In other words, the optical axis of low beam light sourcemodule 13 (low beam light emitting device 14) is parallel to the Y axis.

Lens Body

As illustrated in FIG. 2 through FIG. 5, high beam lens unit 21 and lowbeam lens unit 22 are integrally formed together to form lens body 20.For example, lens body 20 can be made by, for example, injection moldingusing a clear resin such as acryl, polycarbonate, or cyclic olefin. Notethat high beam lens unit 21 and low beam lens unit 22 are not requiredto be integrally formed.

As described above, high beam lens unit 21 is disposed in front of highbeam light source module 10 and configured of three collimatinglenses—first collimating lens 21 a, first collimating lens 21 b, andsecond collimating lens 21 c.

As illustrated in FIG. 6, light emitted forward by first high beam lightemitting device 11 a, first high beam light emitting device 11 b, andsecond high beam light emitting device 11 c passes through firstcollimating lens 21 a, first collimating lens 21 b, and secondcollimating lens 21 c and travels forward as collimated light.

More specifically, first collimating lens 21 a, first collimating lens21 b, and second collimating lens 21 c each have a truncated cone shapewhose diameter increases toward the front. The plurality of high beamlight emitting devices 11 (first high beam light emitting device 11 a,first high beam light emitting device 11 b, and second high beam lightemitting device 11 c) are disposed in the smaller diameter regions ofthese truncated cones (i.e., toward the back).

With this configuration, light emitted by first high beam light emittingdevice 11 a, first high beam light emitting device 11 b, and second highbeam light emitting device 11 c is collimated by totally reflecting offthe inner face of the truncated conical and curved outer wall. Thecollimated light then exits the front surface (planar surface) of firstcollimating lens 21 a, first collimating lens 21 b, and secondcollimating lens 21 c, and travels forward.

Low beam lens unit 22 is disposed in front of low beam light sourcemodule 13. Low beam lens unit 22 is also disposed in front of shield 40.More specifically, low beam lens unit 22 is disposed so as to cover anopening formed in front of shield 40.

The lower portion of low beam lens unit 22 has the shape of a quarterslice of a sphere (one quarter of a sphere). The upper portion of lowbeam lens unit 22 has the shape of one quarter of a sphere, but theportions in front of the three lenses included in high beam lens unit 21are removed.

As illustrated in FIG. 6, light emitted upward by low beam lightemitting device 14 is reflected off reflector 41 of shield 40 and enterslow beam lens unit 22. The optical properties of low beam lens unit 22direct the light, and the light exits forward from the front surface(curved surface) of low beam lens unit 22.

Heat Sink

Heat sink 30 is a heat dissipating component for dissipating heatgenerated by high beam light source module 10 and low beam light sourcemodule 13 (to the atmosphere). Consequently, heat sink 30 is preferablymade of a material with a high rate of heat transfer, such as metal.Heat sink 30 is, for example, an aluminum die cast heat sink made fromcomposite aluminum.

As illustrated in FIG. 5, heat sink 30 is divided into first heat sink31 and second heat sink 32. In other words, first heat sink 31 andsecond heat sink 32 are integrally combined to form heat sink 30. Firstheat sink 31 and second heat sink 32 each include a plurality of heatdissipating fins.

First heat sink 31 is a heat dissipating component for dissipating heatgenerated mainly by high beam light source module 10 (high beam lightemitting device 11). First heat sink 31 includes a mounting surface(installation surface) for mounting high beam light source module 10.

Second heat sink 32 is a heat dissipating component for dissipating heatgenerated mainly by low beam light source module 13 (low beam lightemitting device 14). Second heat sink 32 includes a mounting surface(installation surface) for mounting low beam light source module 13.

In the embodiment, the front end of first heat sink 31 protrudes furtherforward than the front end of second heat sink 32. This allows high beamlight source module 10 to be disposed further forward than low beamlight source module 13.

Shield

Shield 40 is for defining a predetermined cut-off line. Shield 40defines the predetermined cut-off line by shielding a portion of thelight emitted by low beam light source module 13. As illustrated in FIG.5, shield 40 is disposed in the space between low beam lens unit 22 andheat sink 30. Shield 40 may be formed by plastics molding using a heatresistant resin, for example. Note that shield 40 may be metal insteadof resin.

As illustrated in FIG. 5, in the embodiment, reflector 41 is formed onshield 40. Reflector 41 is disposed above low beam light source module13 and reflects light emitted upward by low beam light source module 13.Reflector 41 has a curved reflective surface so as to reflect lightforward at a downward sloping angle toward low beam lens unit 22.Reflector 41 is formed by giving a portion of shield 40 a mirror finish.For example, reflector 41 may be formed on shield 40 by forming a metaldeposition film (for example, an aluminum deposition film) on a portionof shield 40 (heat resistant resin).

Note that reflector 41 and shield 40 may be separate components insteadof being formed integrally.

Area of Illumination

Next, the area illuminated by lighting apparatus 1 according to theembodiment will be described with reference to FIG. 7 through FIG. 11.

FIG. 7 illustrates the driving lane for the automobile according to theembodiment and the oncoming traffic lane.

As described above, lighting apparatus 1 according to the embodiment isused in the headlights of automobile 100. Automobile 100 is driven, forexample, in driving lane 200 illustrated in FIG. 7. For example, FIG. 7illustrates a view forward from the driver's seat of automobile 100.

In the embodiment, the lane to the right relative to the direction oftravel of automobile 100 is driving lane 200 for automobile 100, and thelane to the left relative to the direction of travel of automobile 100is oncoming traffic lane 210 (i.e., right-hand traffic), as illustratedin FIG. 7. Note that the left lane relative to the direction of travelof automobile 100 may be the driving lane for automobile 100 and theright lane relative to the direction of travel may be the oncomingtraffic lane (i.e., left-hand traffic). In the case of left-handtraffic, the area illuminated by (the light distribution pattern of) thehigh beam and the low beam in the case of right-hand traffic may simplybe laterally mirrored.

Note that in FIG. 7, the optical axis of lighting apparatus 1 (theheadlight) is shown by the intersection of horizontal line 220 andvertical line 221. The height (vertical position) of horizontal line 220is, for example, the height of lighting apparatus 1 measured from theground. The position (horizontal position) of vertical line 221 is, forexample, approximately in front (in the driving direction) of vehiclebody 110. In other words, vertical line 221 is equivalent to a verticalplane passing through the optical axis of lighting apparatus 1.

FIG. 8 illustrates the area illuminated by lighting apparatus 1according to the embodiment when the low beams are in use.

Low beam area of illumination 230 illustrated in FIG. 8 is a lightdistribution pattern formed with lighting apparatus 1 when the low beamsare in use. In other words, low beam area of illumination 230 is thearea lighting apparatus 1 illuminates when the low beams are in use. Lowbeam area of illumination 230 is formed so as to achieve a luminousintensity at a point of measurement based on a given standard. Note thatthe luminous intensity of low beam area of illumination 230 is high inthe vicinity of the center and gradually decreases with distance outwardin FIG. 8.

More specifically, when the low beams are in use, lighting apparatus 1illuminates the vicinity in front of automobile 100. For example,lighting apparatus 1 illuminates the side of the road in oncomingtraffic lane 210 in addition to the side of the road in driving lane200. Moreover, lighting apparatus 1 illuminates the portion of drivinglane 200 far ahead that is above horizontal line 220.

Here, lighting apparatus 1 increases the luminous intensity of drivinglane 200 while reducing the luminous intensity of oncoming traffic lane210. To achieve this, low beam area of illumination 230 includes what isknown as a cut-off line. More specifically, the cut-off line is whatproduces the uneven top line of low beam area of illumination 230.

In this way, when the low beams are being used, lighting apparatus 1illuminates the area of driving lane 200 far ahead above horizontal line220 in addition to the immediately surrounding area. This makes itpossible to provide the driver with a more pleasant driving experience.On the other hand, the area above horizontal line 220 on the side ofoncoming traffic lane 210 is not illuminated, which makes it possible toavoid unintentionally blinding oncoming drivers.

FIG. 9 illustrates the area illuminated by lighting apparatus 1according to the embodiment when the high beams are in use.

High beam area of illumination 240 illustrated in FIG. 9 is a lightdistribution pattern formed with lighting apparatus 1 when the highbeams are in use. In other words, high beam area of illumination 240 isthe area lighting apparatus 1 illuminates when the high beams are inuse. High beam area of illumination 240 is formed so as to achieve aluminous intensity at a point of measurement based on a given standard.

When the high beams are in use, regions above horizontal line 220 onboth driving lane 200 and oncoming traffic lane 210 sides of the roadare illuminated. This makes it possible for the driver to more clearlysee objects in the far field including oncoming traffic lane 210 inaddition to driving lane 200, and thus provide the driver with a morepleasant driving experience.

High beam area of illumination 240 illustrated in FIG. 9 is formed byoverlapping three areas of illumination. More specifically, the threeareas of illumination are low beam area of illumination 230 illustratedin FIG. 8, first high beam area of illumination 241 illustrated in FIG.10, and second high beam area of illumination 242 illustrated in FIG.11.

Note that FIG. 10 illustrates the area illuminated by first high beamlamp 3 a and first high beam lamp 3 b included in lighting apparatus 1according to the embodiment. FIG. 11 illustrates the area illuminated bysecond high beam lamp 3 c included in lighting apparatus 1 according tothe embodiment.

Hereinafter, high beam lamp 3, first high beam area of illumination 241,and second high beam area of illumination 242 will be described withreference to FIG. 10 and FIG. 11 while also referring back to FIG. 2through FIG. 5.

First High Beam Lamp

First high beam lamp 3 a includes first high beam light emitting device11 a and first collimating lens 21 a, as illustrated in FIG. 3.Similarly, first high beam lamp 3 b includes first high beam lightemitting device 11 b and first collimating lens 21 b, as illustrated inFIG. 3.

First collimating lens 21 a and first collimating lens 21 b aresubstantially circular in front view, as illustrated in FIG. 3. Firstcollimating lens 21 a and first collimating lens 21 b are designed so asto have optical axes that align with the traveling direction ofautomobile 100 (Z axis) when lighting apparatus 1 is attached toautomobile 100.

The area illuminated by first high beam lamp 3 a and first high beamlamp 3 b is first high beam area of illumination 241 illustrated in FIG.10. Note that first high beam lamp 3 a and first high beam lamp 3 billuminate approximately the same area. In other words, first high beamlamp 3 a and first high beam lamp 3 b both illuminate first high beamarea of illumination 241.

The center of the area illuminated by first high beam lamp 3 a is, forexample, the centroid of the area, and the center of the areailluminated by first high beam lamp 3 b is, for example, the centroid ofthe area. More specifically, the center of the area illuminated by firsthigh beam lamp 3 a and first high beam lamp 3 b is the center (centroid)of first high beam area of illumination 241.

For example, the center of first high beam area of illumination 241 islocated in the vicinity of where driving lane 200 and horizontal line220 intersect in the distance, as illustrated in FIG. 10. For example,the center of first high beam area of illumination 241 is located at theintersection of horizontal line 220 and vertical line 221.

Second High Beam Lamp

Second high beam lamp 3 c includes second high beam light emittingdevice 11 c and second collimating lens 21 c, as illustrated in FIG. 3.The area illuminated by second high beam lamp 3 c is second high beamarea of illumination 242 illustrated in FIG. 11. As can be seen bycomparing FIG. 10 and FIG. 11, first high beam area of illumination 241and second high beam area of illumination 242 are different from eachother.

More specifically, the optical axis of second collimating lens 21 c isoblique to the optical axes of first collimating lens 21 a and firstcollimating lens 21 b, as illustrated in FIG. 4. For example, theoptical axis of second collimating lens 21 c intersects the optical axisof first collimating lens 21 a at an angle greater than 0 degrees andless than or equal to 10 degrees. In other words, second collimatinglens 21 c is oriented at an angle such that its optical axis pointstoward oncoming traffic lane 210.

This makes it possible to horizontally space apart the center of thearea illuminated by second high beam lamp 3 c and the center of the areailluminated by first high beam lamp 3 a and first high beam lamp 3 b. Inother words, as can be seen by comparing FIG. 10 and FIG. 11, the centerof second high beam area of illumination 242 and the center of firsthigh beam area of illumination 241 are horizontally spaced apart fromeach other.

More specifically, the center of second high beam area of illumination242 is situated around horizontal line 220 to the side of oncomingtraffic lane 210 (the side away from driving lane 200). In other words,the center of second high beam area of illumination 242 is located agiven distance away from the intersection of vertical line 221 andhorizontal line 220 in a direction toward oncoming traffic lane 210.

Second collimating lens 21 c is substantially elliptical in front view.In other words, second collimating lens 21 c has a different shape thanfirst collimating lens 21 a. More specifically, the shape of thereflective surface (i.e., the side surface) of second collimating lens21 c is designed to be different than the shape of first collimatinglens 21 a.

Note that, as illustrated in FIG. 3, first collimating lens 21 a andsecond collimating lens 21 c are substantially circular in front view,but first collimating lens 21 a is closer to a true circle than secondcollimating lens 21 c.

As a result, second high beam area of illumination 242 has a horizontalwidth that is greater than the horizontal width of first high beam areaof illumination 241. More specifically, second high beam area ofillumination 242 has a maximum horizontal width that is greater than themaximum horizontal width of first high beam area of illumination 241. Asillustrated in FIG. 10 and FIG. 11, second high beam area ofillumination 242 is substantially elliptical, while first high beam areaof illumination 241 is substantially circular.

Note that, for example, first high beam area of illumination 241 may beincluded in second high beam area of illumination 242. In other words,second high beam area of illumination 242 may be larger than first highbeam area of illumination 241. Moreover, first high beam area ofillumination 241 may have a vertical width (i.e., height) that isgreater than the height of second high beam area of illumination 242.

High Beam Lamp Arrangement

As illustrated in FIG. 3 and FIG. 4, first high beam lamp 3 a and firsthigh beam lamp 3 b are horizontally offset from each other. Moreover, asillustrated in FIG. 3, first high beam lamp 3 a and first high beam lamp3 b are vertically offset from each other.

More specifically, first high beam light emitting device 11 a and firsthigh beam light emitting device 11 b are spaced apart from each otherboth horizontally and vertically. First collimating lens 21 a and firstcollimating lens 21 b are also offset from each other both horizontallyand vertically.

This allows for the horizontal width of the space occupied by first highbeam lamp 3 a and first high beam lamp 3 b to be reduced to less thanwhen aligned on a single horizontal line. This makes it possible toreduce the overall size of lighting apparatus 1.

First high beam lamp 3 b and second high beam lamp 3 c are also offsetfrom each other both horizontally and vertically. More specifically,first high beam light emitting device llb and second high beam lightemitting device 11 c are spaced apart from each other both horizontallyand vertically. First collimating lens 21 b and second collimating lens21 c are also offset from each other both horizontally and vertically.

This makes it possible to reduce the overall size of lighting apparatus1.

Note that when viewed from the front, first high beam lamp 3 a, firsthigh beam lamp 3 b, and second high beam lamp 3 c are disposed in thelisted order from right to left. In other words, second high beam lamp 3c is disposed on the side opposite oncoming traffic lane 210, but thearrangement of the high beam lamp is not limited to this example. Secondhigh beam lamp 3 c may be disposed in the middle position and,alternatively, may be disposed on the side nearest oncoming traffic lane210.

Moreover, the number of first high beam lamps included in lightingapparatus 1 may be one, and the number of second high beam lampsincluded in lighting apparatus 1 may be more than one.

On/Off Control

FIG. 12 is a block diagram illustrating a configuration relating tolighting functions of automobile 100 according to the embodiment. Inother words, FIG. 12 is an illustration of when lighting apparatus 1according to the embodiment is installed in automobile 100.

As illustrated in FIG. 12, automobile 100 includes lighting apparatus 1,engine control unit 140, and switch 150. Lighting apparatus 1 includes amain body (high beam light source module 10 and low beam light sourcemodule 13) and lighting controller 130.

Lighting controller 130 turns on first high beam light emitting device11 a, first high beam light emitting device 11 b, second high beam lightemitting device 11 c, and low beam light emitting device 14 when thehigh beams are turned on. In other words, lighting controller 130 turnson all light emitting devices when the high beams are turned on. Whenthe low beams are turned on, however, lighting controller 130 only turnson low beam light emitting device 14.

Engine control unit (ECU) 140 controls the engine of automobile 100.Engine control unit 140 is, for example, a microcontroller. Lightingcontroller 130 and switch 150 are connected to engine control unit 140.Engine control unit 140 transmits an instruction input from switch 150to lighting controller 130.

Switch 150 switches lighting apparatus 1 on and off. More specifically,switch 150 switches the low beams on and off and switches the high beamson and off. Even more specifically, switch 150 switches each of low beamlight emitting device 14, first high beam light emitting device 11 a,first high beam light emitting device 11 b, and second high beam lightemitting device 11 c on and off.

For example, when driving at night and an oncoming vehicle is present,the driver of automobile 100 operates switch 150 to cause lightingapparatus 1 to project the low beam. More specifically, lightingcontroller 130 turns on only low beam light emitting device 14 toachieve low beam area of illumination 230 illustrated in FIG. 8.

Moreover, when driving at night and an oncoming vehicle is not present,the driver of automobile 100 operates switch 150 to cause lightingapparatus 1 to project the high beam. More specifically, lightingcontroller 130 turns on low beam light emitting device 14, first highbeam light emitting device 11 a, first high beam light emitting device11 b, and second high beam light emitting device 11 c to achieve highbeam area of illumination 240 illustrated in FIG. 9.

Summary

With a conventional lighting apparatus, for example, when driving atnight and an oncoming vehicle is present, the low beam light emittingdevice is turned on, and when driving at night and an oncoming vehicleis not present, the high beam light emitting device is turned on. Inother words, either the low beam light emitting device or the high beamlight emitting device is exclusively turned on depending on the presenceof an oncoming vehicle.

In this case, the high beam light emitting device must achieve anextremely high illuminance, which makes it impossible to reduce powerconsumption.

For example, when the area that is illuminated for high beam use isachieved with one light emitting device or a plurality of light emittingdevices that illuminate the same area, the luminous intensity must beincreased excessively. For example, when the light emitting device isturned on so as to achieve a luminous intensity at a measurement point Astipulated in a given standard, the luminous intensity at a differentmeasurement point B may be enough to fulfill the luminous intensityrequired by the standard. In other words, it is possible to fulfill theluminous intensity required by the standard even if the luminousintensity at measurement point B is reduced. In other words, projectinglight of an excessive luminous intensity at measurement point B is aninefficient use of power.

In light of this, according to the embodiment, lighting apparatus 1 is alighting apparatus for vehicle use that projects light forward, andincludes: base 2, low beam lamp 4 including low beam light emittingdevice 14 disposed on base 4; first high beam lamp 3 a including firsthigh beam light emitting device 11 a disposed on base 4; second highbeam lamp 3 c including second high beam light emitting device 11 cdisposed on base 4; and lighting controller 130 configured to turn onlow beam light emitting device 14, first high beam light emitting device11 a, and second high beam light emitting device 11 c when high beamsare turned on. The center of an area illuminated by first high beam lamp3 a and the center of an area illuminated by second high beam lamp 3 care horizontally spaced apart from each other.

Accordingly, power consumption can be reduced.

The center of the area illuminated by first high beam lamp 3 a and thecenter of the area illuminated by second high beam lamp 3 c arehorizontally spaced apart from each other. In other words, first highbeam lamp 3 a and second high beam lamp 3 c illuminate different,overlapping areas such that one area supplements the other. For example,by having one of first high beam lamp 3 a and second high beam lamp 3 cilluminate a region including measurement point A and the other of firsthigh beam lamp 3 a and second high beam lamp 3 c illuminate a regionincluding measurement point B, first high beam lamp 3 a and second highbeam lamp 3 c can achieve a luminous intensity necessary for each area.This makes it possible to reduce wasteful consumption of power and thusreduce power consumption while maintaining luminous intensity. In otherwords, compared to the example where the area of illumination is formedby either exclusively turning on the low beam light emitting device orexclusively turning on the high beam light emitting device, the amountof luminance produced by each lighting element and the amount of powerconsumed is reduced.

Moreover, for example, the horizontal width of the area illuminated bysecond high beam lamp 3 c is greater than the horizontal width of thearea illuminated by first high beam lamp 3 a.

For example, as illustrated in FIG. 10, since first high beam lamp 3 aand first high beam lamp 3 b illuminate a narrow area of an extension ofdriving lane 200, power consumption is reduced by reducing the amount oflight output while still being able to illuminate the near portion ofdriving lane 200 to a sufficient brightness.

Moreover, as illustrated in FIG. 11, since second high beam lamp 3 cilluminates a horizontally elongated area (a narrow area) includingdriving lane 200 and oncoming traffic lane 210, it is still possible toilluminate the shoulder of the road adjacent to driving lane 200 as wellas the area next to the shoulder, and the shoulder of the road adjacentto oncoming traffic lane 210 as well as the area next to the shoulder,to a sufficient brightness, even though power consumption is reduced byreducing the amount of light output.

Additionally, as illustrated in FIG. 9, low beam lamp 4 illuminates anarea in front of and immediately surrounding automobile 100 that ishorizontally wide (low beam area of illumination 230). With this, eachof the areas can be sufficiently illuminated when the high beams are inuse.

Here, since first high beam lamp 3 a, first high beam lamp 3 b, secondhigh beam lamp 3 c, and low beam lamp 4 each illuminate a narrow area,power consumption is reduced.

Moreover, for example, first high beam lamp 3 a includes firstcollimating lens 21 a, second high beam lamp 3 c includes secondcollimating lens 21 c, and the optical axis of second collimating lens21 c is oblique to the optical axis of first collimating lens 21 a.

With this, second high beam lamp 3 c can be achieved with a simplestructure, since angling the optical axis of the lens is all that isrequired.

Moreover, for example, first collimating lens 21 a is substantiallycircular in front view and second collimating lens 21 c is substantiallyelliptical in front view.

With this, first high beam lamp 3 a, first high beam lamp 3 b, andsecond high beam lamp 3 c can be achieved with a simple structure, sinceshaping the respective lenses differently is all that is required.

Moreover, for example, lighting apparatus 1 includes a plurality offirst high beam lamps—first high beam lamp 3 a and first high beam lamp3 b—that are horizontally offset from each other.

This makes it possible to reduce the overall size of lighting apparatus1.

Moreover, for example, first high beam lamp 3 a and first high beam lamp3 b are vertically offset from each other.

This makes it possible to reduce the overall size of lighting apparatus1.

Moreover, for example, first high beam lamp 3 a, first high beam lamp 3b, and second high beam lamp 3 c are vertically offset from each other.

This makes it possible to reduce the overall size of lighting apparatus1.

Moreover, for example, the automobile according to the embodimentincludes lighting apparatus 1, vehicle body 110 including lightingapparatus 1 in a front portion, and engine control unit 140 connected tolighting controller 130.

This makes it possible to improve fuel efficiency and, for example,extend the distance capable of being driven, by reducing powerconsumption.

Variations

Although the lighting apparatus, automobile, etc., according to thepresent disclosure are described based on an embodiment, the presentdisclosure is not limited to this embodiment.

For example, in the above embodiment, second collimating lens 21 c isexemplified as having a truncated conical shape and being disposed at anangle; but second collimating lens 21 c is not limited to this example.For example, second collimating lens 21 c may have the shape of atruncated cone that is sliced at an angled. In other words, the frontsurface (surface from which light exits) of the truncated cone may beangled with respect to the axis of the truncated cone.

Moreover, for example, the optical axis may be angled by treating thesurface of the collimating lens. More specifically, a microlens may beformed in the front surface of the collimating lens to change thedirection of travel of light. In this case, the surface of thecollimating lens in the vicinity of the peripheral edge of the lens inparticular may be untreated. This increases the ability of thecollimating lens to collect light even further.

Moreover, for example, in the above embodiment, second high beam area ofillumination 242 is exemplified as having a horizontal width that isgreater than the horizontal width of first high beam area ofillumination 241, but this example is not limiting. For example, firsthigh beam area of illumination 241 may have a horizontal width that isgreater than the horizontal width of second high beam area ofillumination 242. More specifically, second collimating lens 21 c mayhave a shape that is closer to a true circle than first collimating lens21 a and first collimating lens 21 b are.

Moreover, for example, the center of the area of illumination of firstcollimating lens 21 a and first collimating lens 21 b—that is, thecenter of first high beam area of illumination 241—is exemplified asbeing located at the intersection of horizontal line 220 and verticalline 221, but this example is not limiting. The center of first highbeam area of illumination 241 may be offset from the intersection ofhorizontal line 220 and vertical line 221 toward oncoming traffic lane210 or the shoulder of the road

In other words, the respective areas of illumination, and centersthereof, formed by first high beam lamp 3 a and second high beam lamp 3c are not limited to the above example. Moreover, lighting apparatus 1may include a third high beam lamp that forms a third area ofillumination different in shape from both first high beam area ofillumination 241 and second high beam area of illumination 242. In thiscase, lighting apparatus 1 may include the third high beam lamp as asubstitute for first high beam lamp 3 b and, alternatively, may includethe third high beam lamp in addition to first high beam lamp 3 a, firsthigh beam lamp 3 b, and second high beam lamp 3 c.

Moreover, for example, in the above embodiment, high beam light sourcemodule 10 and low beam light source module 13 are exemplified as beingvertically offset from each other, but this example is not limiting. Forexample, high beam light source module 10 and low beam light sourcemodule 13 may be aligned along a single horizontal line. Moreover, bothhigh beam light emitting device 11 and low beam light emitting device 14may be mounted on a single substrate.

Moreover, for example, in the above embodiment, vehicle body 110 isexemplified as including two lighting apparatuses 1 (two headlights120), but vehicle body 110 is not limited to this example. For example,vehicle body 110 may include three or more lighting apparatuses 1, suchas two lighting apparatuses 1 on the right side and two lightingapparatuses 1 on the left side, and, alternatively, may include only onelighting apparatus 1.

For example, in the above embodiment, lighting apparatus 1 isexemplified as being applied to a headlight that projects a high beamand a low beam, but lighting apparatus 1 may be applied to an auxiliarylight such as a fog light or a daylight/daytime running light (DRL).

Moreover, although the automobile is exemplified as a four-wheeledautomobile in the above embodiment, the automobile may be otherautomobiles such as a two-wheeled automobile.

Moreover, in the above embodiment, the light emitting devices areexemplified as LEDs, but the light emitting devices may be semiconductorlasers, organic electroluminescent (EL) devices, or non-organic ELdevices.

While the foregoing has described what are considered to be the bestmode and/or other examples, it is understood that various modificationsmay be made therein and that the subject matter disclosed herein may beimplemented in various forms and examples, and that they may be appliedin numerous applications, only some of which have been described herein.It is intended by the following claims to claim any and allmodifications and variations that fall within the true scope of thepresent teachings.

What is claimed is:
 1. A lighting apparatus for vehicle use thatprojects light forward, the lighting apparatus comprising: a base; a lowbeam lamp including a low beam light emitting device disposed on thebase; a first high beam lamp including a first high beam light emittingdevice disposed on the base; a second high beam lamp including a secondhigh beam light emitting device disposed on the base; and a lightingcontroller configured to turn on the low beam light emitting device, thefirst high beam light emitting device, and the second high beam lightemitting device when high beams are turned on, wherein a center of anarea illuminated by the first high beam lamp and a center of an areailluminated by the second high beam lamp are horizontally spaced apartfrom each other.
 2. The lighting apparatus according to claim 1, whereina horizontal width of the area illuminated by the second high beam lampis greater than a horizontal width of the area illuminated by the firsthigh beam lamp.
 3. The lighting apparatus according to claim 1, whereinthe first high beam lamp includes a first collimating lens, the secondhigh beam lamp includes a second collimating lens, and an optical axisof the second collimating lens is oblique to an optical axis of thefirst collimating lens.
 4. The lighting apparatus according to claim 3,wherein the first collimating lens is substantially circular in frontview, and the second collimating lens is substantially elliptical infront view.
 5. The lighting apparatus according to claim 1, wherein thefirst high beam lamp comprises a plurality of first high beam lamps, andthe plurality of first high beam lamps are horizontally offset from eachother.
 6. The lighting apparatus according to claim 5, wherein theplurality of first high beam lamps are vertically offset from eachother.
 7. The lighting apparatus according to claim 1, wherein the firsthigh beam lamp and the second high beam lamp are vertically offset fromeach other.
 8. An automobile comprising: the lighting apparatusaccording to claim 1; a vehicle body including the lighting apparatus ina front portion; and an engine control unit connected to the lightingcontroller.